Saturday, March 24, 2007

I purchased this truck right after my 3rd speeding ticket with the 1500. For the first time in my life, I could go shopping for a truck to support my HF mobile habits. It's a 2003 Dodge Quad Cab Turbo Diesel. It was great not having any RFI from an ignition system! This truck did produce some RFI on 20m, especially while towing, or hauling heavy loads. This truck is just over 20' long. That makes the exhaust pipe just over a quarter wave on 20m. Grounding the pipe as near to the end as possible cured the noise. I also had some injector pump noise, very low around S2, and that was cured by attaching 3/4" clamp-on ferrite chokes. I put three of them on the cable that runs out of the pump, then on to the injectors. With this truck, I can run with no noise blanker, and no DSP. I have more problems with the other vehicles around me, and power lines.

Profile of the beast. It's difficult to see, but there are 3 antennas mounted through the roof, right between the back door and the shell.

Looking at the rear of the truck. The HF antenna is a KJ7U Shorty II, 160M-6M screwdriver antenna. You can read more about them at: http://www.kj7u.com.

Oblique shot - sure looks long! It is, especially in parking lots.

You can see the highband antennas through the roof. Left antenna is 220, middle is scanner, right is 2/440.

This was my 4th and final attempt at installing a HI-Q 3/80 antenna. I also attempted to mount the HI-Q under the shell, first time horizontally, then vertically. I also tried mounting it in the same location as the KJ7U, but that proved to be a bad place. The HI-Q is very heavy, and long antenna so it would swing around too much. Was a real problem pulling into driveways. No matter what I did, or how I mounted the HI-Q, I just couldn't get it to work well on this truck.

Caphat on the HI-Q. Overall length, 13' 6".

I'm starting to install the KJ7U antenna between the shell and the top of the bed. The photo above is the final mount before sandwiching it between the shell and bed. It's bolted to the top of the bed rail, and again up through the shell. Take a look at the inside photo below for bracing to the shell.

Finished mount, with antenna post installed.

Inside HF antenna wiring. The box is part of the remote HF SWR/Wattmeter. The grey cable going off to the left connects to the meter in the cab. Red wire is for power. 1" silver braid attaches to a bolt going through the bed. There's another short ground strap going from this bolt right to the frame. The three bolts you see at the top of the picture is back bracing for the mount. There's a 1"x4" piece of aluminum between the nuts and the shell.

Mount with antenna attached. There's enough of a gap between the shell and bed to let the cables fit through without getting crunched.

Finished mount. Neat little antenna, at 20" tall, it can tune 160M through 6M. It's a great match for the IC-7000. It doesn't swing around as much as the HI-Q, even when it's fully extended on 160M. I still think having the coil retract into the base is a better approach than the HI-Q. This antenna is less susceptible to noise, and as Don Johnson attests, the coil that's in the tube actually acts like it's part of the base. The HI-Q, with the tap inside the coil leaves the lower half of the coil exposed, and I think that's why it was a noisier antenna than the Shorty II.

Amp installed. It fits nicely behind the front seats, right on the transmission hump. Fans are very quiet, and I can easily reach the switches. What you can't see is the 8 GA power cables, coax and TR cable. They all go under the center console, and are hidden from view, and people's feet.

40 watts drive, puts out just over 500 watts. The alternator in this truck is rated at 135 amps, so it can support this amp with no problems. When it's cold out, I have to wait for the glow screens to turn off. The alternator can't handle having those screens running, and the amp at the same time. 500 watts seems to be the sweet spot. It's enough power to overcome the losses in the antenna. Works very well running around town on 160M in the evenings. My longest contact on 160 is 200 miles.

I first installed an Icom IC-706MKIIG, and ran with that for 3 years. I needed an HF rig for the house, and decided to upgrade the truck to the IC-7000. What a difference! Don't get me wrong, the 706 is a great rig, but the 7000 is night and day difference. The receiver is incredible in the 7000, and having IF DSP makes it a rig that's very easy on the ears. The color display is amazing as well, but difficult to read the way I have the rig installed. So, I noticed the 7000 has a video out jack, and thought installing an LCD monitor would be a great addition to the rig.

An overall shot of the interior. From left to right, IC-2710H, IC-7000, Pro-2066 and IC-35A. The cabinet is custom made to fit on the transmission hump. It takes just a few minutes to unplug everything and remove all the equipment. The HF SWR/Wattmeter is an Ameritron AWM-35. It's mounted on a custom mount that I bought from Pro.Fit. It's called a vehicle specific mount, and well worth the money.

Shot with the rig and monitor on. I can read everything with ease. The LCD monitor is a 7" Pyle that can be found just about anywhere for about $120. The only problem I have is on 20M where it suffers from pretty heavy RFI and gets scrambled. I'll probably fix that with a custom made cable between the monitor and rig.

This entire project has taken three and a half years to get to this point. I do have plans to install a small laptop to run Winlink, logging, and other digital modes when I'm parked. At this point, I'm very happy with this installation, and I'll be keeping it for many years.

Sunday, March 11, 2007

This was my 3rd HF mobile. It had the usual Ford fuel pump noise problems as a lot of Ford vehicles of this vintage. I couldn't obtain the filtering kit, and the professional installation required, so using my ham ingenuity, I came up with another solution.

RadioShack carries a 10 amp RFI filter for car stereos. I figured if it could stop RFI from going into something, it could stop RFI from coming out of the fuel pump. I was correct! It worked like a charm, and I didn't have to have the fuel tank dropped to install the filters on the in-tank fuel pump. I installed the RFI filter right on top of the fuel tank, as close to the pump as possible.

Inside the cab, I had a Yaesu FT-767GXii, which worked very well. Below the Yaesu is an Icom 2710 dual-bander, and where the car stereo used to be is a RadioShack mobile scanner. This was a very easy to use HF mobile, and it looked good too.

I used a DSP speaker to help out with some of the noise, and it worked well. It's actually mounted behind the driver's seat.

Looking under the shell, I mounted an original Don Johnson DK3 Screwdriver The red wire angled across the top of the shell.

Since the DK3 is variable geometry antenna - meaning, it gets longer as you go down in frequency - I used a spring to keep the wire taught. I don't have a picture of the outside of the shell, so I'll have to describe it. I installed a ball mount at the top of the shell. The red wire connected to the inside of the ball mount. Outside I had a 102" whip attached to the ball. Doing all the math, that works out to a 1/4 wave on 20M going down the road. This performed very well, especially on 40 and 80M. 20M was just as good as being at home with a vertical.

I sold the truck sometime in 2001 for a fire engine red Dodge 1500 sport truck. I only installed the 2710 in that truck. I couldn't run HF since it was a leased vehicle.

About Me

I've been licensed since 1982 and have always held the call KA6WKE. I used to be heavily involved in HF mobile but with a job change that doesn't require commuting, I'm now a fixed station. The antenna farm is a full size 40m loop for HF, JPole for 2m/70cm. Rigs are IC-7000 & IC-706MKIIg. You can email me at ka6wke@gmail.com & yes, I'll QSL!
73